Error on displaying Post in a particular custom taxonomy…

Catchable fatal error: Object of class WP_Query could not be converted to string in

I want to display all post in a particular taxonomy but the error above always appearing.. i delete some data in database but nothing happens i tried to reinstall it but still the same.. can anyone help me about this prob…

this is the code

<?php
$args = array(
‘post_type’ => ‘content’,
‘tax_query’ => array(
array(
‘taxonomy’ => ‘wawa’,
‘field’ => ‘slug’
)
)
);
$query = new WP_Query( $args );

echo $query;
?>